1. Field of the Invention
The invention relates to a portable computer with a desktop type processor; in particular, to a portable computer that can effectively drive a desktop type processor in a power saving mode.
2. Description of the Related Art
Recently, portable computers have become lighter and easier to carry, hence they are widely used. As the technology of portable computers has developed, they have become as powerful and functional as their desktop counterparts. Although portable computers are convenient, they are still too expensive price for many people. Thus, reducing the cost of portable computers has become an important issue for manufacturers. One way to reduce the cost is to replace the portable type processor with a desktop type processor so that portable computer prices can be reduced.
Referring to FIG. 1a, a conventional portable computer 10 with a desktop type processor 12 is shown. The desktop type processor 12 outputs a signal to a clock generator 11 via an I2C bus 14 so that the clock generator 11 can acknowledge the type of desktop type processor 12. Thus, the clock generator 11 can output a clock signal corresponding to the processor 12 so as to determine the operational frequency and operational voltage of the processor 12. It is noted that before the outer operational voltage determined by the clock generator 11 enters the processor 12, it passes through a DC-DC voltage converter 12 so as to be transferred into an inner operational voltage suitable for use by the processor 12.
It is understood that the portable computer 10 includes a chipset and a memory and other devices therein. Operational frequencies and voltages of the chipset and the memory and other devices correspond to the operational frequency and voltage of the processor 12.
In the conventional portable computer 10, when the desktop type processor 12 is driven in a power saving mode, the throttling manner as shown in FIG. 1b is utilized. Specifically, the processor 12 is sometimes operated by using higher power (about 30 W), and is sometimes operated by using lower power (about 6 W).
That is, as shown in FIG. 1b, the processor 12 sometimes operates in normal mode (which consumes more power) while it is in the power saving mode. In addition, the operational voltage of the processor 12 is proportional to the consumed power. Since the processor 12 in power saving mode sometimes requires higher power consumption to operate, the processor 12 is operating in at the normal voltage level. Thus, the purpose of reduced power consumption cannot be achieved.
In addition, as shown in FIG. 1b, since power consumption fluctuates, the processor 12 also operates with fluctuating voltage, thus reducing the reliability of the processor.